This invention relates to a tool, machine and method for profiling.
FIG. 5 shows a sectional view of a conventional rotary tool for milling, and FIG. 6 shows a profiling method using a conventional tool and method. Such a conventional tool generally consists of a shank section 2 secured to the associated machine tool and a cutter 1 for machining a workpiece 4. When performing a machining operation such as chamfering, stepping, etc. with high accuracy on a workpiece to shape it in conformity with a reference finish surface 5 by using a conventional rotary tool as shown in the drawings, it has been necessary to perform such a machining operation while the workpiece is fixed on the same equipment as the one used for finishing the workpiece reference surface, or to accurately secure the workpiece in position on another equipment and then perform such machining on the workpiece.
When performing chamfering or stepping on a workpiece to shape it in conformity with a particularly complicated curved surface, the machining is generally performed while the workpiece is fixed on the same equipment as the one used for finishing the workpiece reference surface, or the workpiece is positioned with high accuracy on an equipment different from the one used for finishing the workpiece reference surface and then the machining is performed by using a machine equipped with a high-precision NC controller.
However, when, as shown in FIG. 3, chamfering is to be performed with high accuracy on an intermediate portion 6C between an upper surface 7C and a side surface 5C of a spiral wall, the chamfering has to be performed with the same equipment as that used in the finishing of the upper and side surfaces of this spiral wall, without releasing the chuck, with the result that the machining requires much time and necessitates an increase in equipment size and an enhancement in accuracy. There is a machining method available according to which wall-surface finishing and chamfering are conducted simultaneously by using a tool consisting of a combination of a wall-finishing tool and a cutter for chamfering. This method, however, has a problem in that when a strict dimensional precision is required, it is difficult to prepare the tool, which cannot be exactly shaped into a desired configuration, thus making it difficult to attain a high level of dimensional precision. On the other hand, when wall-surface finishing and chamfering are performed by separate processes, angular and center deviations with respect to the spiral configuration will be generated due to the re-chucking involved, thereby making it difficult to obtain a uniform, high-precision chamfered configuration. To achieve such a chamfered configuration, the workpiece must be positioned accurately, and the equipment precision must be enhanced, resulting in an increase in mounting time and costs.
Further, with the conventional methods, a high-precision, NC-controlled machine tool is required, resulting in a high equipment cost and much time being needed to design and mount jigs. Further, it has been impossible to perform profiling with high accuracy on surfaces such as casting surfaces, which exhibit a variation in configurational precision.